Firefighters or members of comparable rescue teams are confronted with various situations. The spectrum ranges from technical assistance over firefighting to the use of hazardous materials. Different components are needed for personal protection. Heavy respirators are used in firefighting, using, for example, full-face mask (full breathing mask) combined with a compressed air breathing apparatus or a closed-circuit respirator.
Besides the protection from smoke poisoning or the like, the members of rescue teams also require adequate communication. They work alone or in teams of two during missions depending on the needs. The communication with the mission leader and within the team is absolutely necessary for a smooth mission. The use of analog or digital radio equipment is known. A marked improvement compared to working with a manual radio equipment is offered by the integration of the radio equipment in the corresponding protective headgear in the form of a headset solution. This is known, for example, from U.S. Pat. No. 5,463,693 B. A microphone for receiving speech signals is integrated in this case in the mask and a received speech signal is transmitted by means of a loudspeaker acting as an earphone.
The need for a power source that can be carried along and that is usually designed in the form of primary batteries, i.e., non-rechargeable batteries, is problematic in such communication systems. Depending on the power demand, service lives of about 8 hours can be reached. This represents a considerable effort in terms of work and testing for users of such protective headgear, especially for firefighters, as well as equipment maintenance staff, because the power sources of such communication systems must be tested regularly in respect to the corresponding state of charge and new batteries may have to be inserted.